以锌空心阴极灯作为光源,用火焰原子吸收光谱法测定了铝合金中铜量。试样溶解于盐酸及硝酸中,并在含有硝酸(1+1)溶液3.0 mL的50 mL酸性溶液中进行测定。在试样溶液中还加入5 g·L-1乳化剂OP溶液1.5 mL作为增敏剂,30 g·L-1镧(Ⅲ)溶液4.0 mL作为释放剂;后者的加入使硅、铝、镁、镍、锰、钙、钴及铁的允许共存量有显著提升。按此条件分析过程中不存在背景吸收干扰。测得吸光度与相应铜(Ⅱ)的质量浓度在6.0 mg·L-1以内呈线性关系,其检出限(3s/k)为0.011 2 mg·L-1。应用此方法分析了一件铝合金试样,测得其铜量的平均值为1.656 mg·g-1,测定值的相对标准偏差(n=6)为1.3%。同一试样,改用铜空心阴极灯进行分析,测得铜量的平均值为1.670 mg·g-1,相对标准偏差(n=6)为0.92%。t-检验结果表明:用两种不同光源所测得的铜量的结果之间无显著性差异。

Zinc hollow cathode lamp was used as light source in the FAAS determination of copper in aluminum alloy. The sample was dissolved in HCl and HNO3, and the determination was carried out in an acidic medium containing 3.0 mL of HNO3(1+1) per 50 mL of sample solution. 1.5 mL of 5 g·L-1 emulsifier OP solution were added as sensitizer, and 4 mL of 30 g·L-1 La(Ⅲ) solution were added as liberating agent which was used also to promote the tolerance of co-existing Si, Al, Mg, Ni, Mn, Ca, Co and Fe to significant extents. No background absorption was observed in the analysis. Linear relationship between values of absorbance and mass concentration of Cu(Ⅱ) was obtained in the range within 6.0 mg·L-1, with detection limit (3s/k) of 0.011 2 mg·L-1. An aluminum sample was analyzed by this method for its copper content, giving an average value of 1.656 mg·g-1 with value of RSD (n=6) 1.3%. By analyzing the same sample by using copper hollow cathode lamp, the av. content of Cu found was 1.670 mg·g-1 and the RSD (n=6) found was 0.92%. As shown by the result of t-test, no significant difference was found between the results using the 2 light sources.